The present invention relates to compositions for use in the washing of fabrics in washing machines. More particularly, the invention is directed to a composite, unitary packet including, as distinct components, a detergent or washing composition and a fabric treating composition, and in which the several different components are released in a predetermined, controlled sequence.
Many different types of fabric washing preparations have been developed for use in rotary and agitator-type washing machine. The commercial embodiments of these washing compositions have taken various physical forms. The products currently being marketed include many and varied functional chemical ingredients for both general an specialized applications.
Special products, each intended to perform a principal limited function such as fabric cleaning, bleaching, fabric "softening" and freeing fabric of static electrical charges have been offered to the consumer. In addition, multi-purpose compositions which include two or more different functional components, intermixed or combined physically have also been widely promoted.
The addition, all at the same time, of separate compositions such as detergents, fabric softeners, and anti-static agents into the tub of a washing machine has proven unsatisfactory in that interference and interaction between the various chemical ingredients occurs with the result that there is product deactivation and failure. As a result, the full intended function or role of at least one of the "special" agents added is not realized. In some instances a given functional utility is lost entirely.
The alternative procedure of adding each specialized product separately but in turn, at sequential time-spaced increments of the washing operation, is exceedingly inconvenient in that it is necessary that one be present during and to follow the time-controlled stages of the washing cycle.
The problems described above have been recognized; various approaches have been explored to provide solutions. Products have been devised which contain multi-functional compositions, but which, upon introduction into a washing machine, act to release the different functional ingredients in a particular sequence, for example, the bleach being released only after the washing cycle has been in progress for some period of time.
The general method for achieving such delayed or sequential addition or incorporation of ingredients into a fabric washing system is to use specially controlled, multi-compartment pouches, bags, envelopes or sachets, including such structures having walls of varying water permeability. In other such pouches, the walls themselves are impermeable to water, but are water-disintegratable. Water disintegrateable seals have been used to control or delay the release of a particular packaged ingredient. In still other arrangements a combination of water impermeable and water permeable walls and/or seals has been employed. The structural composition of the pouch walls themselves includes plastics, woven and non-woven fabrics, and porous walls of plastic or fabric, but coated with a permanent water sealant film or with a film which dissolves in water at a rate dependent upon the coating composition and the thickness.
In still other arrangements the release of a particular ingredient from a given compartment of a composite package has been rendered temperature-dependent so that above a critical temperature the confining wall disintegrates or becomes permeable to the encapsulated, or confined ingredient. Another method to achieve a time-spaced, sequential release of two component compositions has been totally to encapsulate or to encase one component physically within the other. In still another type of arrangement coatings the solubility of which depends upon the pH of the ambient aqueous system are used to control the release of a confined composition.
In some of the packages of the type referred to, the precise properties, including the critical solubilities of the structural walls of the pouches used, have been difficult to control. Requisite reliability and consistency of operation have not been realized. Others of the packages have lacked the physical strength and have fractured or otherwise failed during shipment and handling. In still others fusion seals or adhesive seals have opened prematurely or have failed to open as intended, or have otherwise proved unreliable and inoperative. Products of the encasement or encapsulation type and without protective mechanical enclosures have fractured prematurely resulting in simultaneous dissolution, thus obviating the intended utility.
It is, therefore, a principal aim of the present invention to provide a multi-functional fabric washing and treating product in which separate components are released into the washing system sequentially, at time-spaced intervals, in a controlled manner, and in which shortcomings and deficiencies of prior art preparations have been overcome.